6/8 PHILOSOPHICAL TRANSACTIONS. [anNO I672, 



After this he inquires^ whether ever such great vessels of so many tiers of 

 oars, sitting in so many diiFerent heights, were ever actually built ? And, if 

 they were, whether they ever came abroad to fight ? Especially such a one as 

 that of Philopater's is recorded to have been, of 40 tiers, requiring above 4000 

 rowers ; and that of Ptolemaeus Philadelphus, of 30 tiers, having more than 

 3000 rowers ; and another of 20 rows, requiring 2000. Hereupon our author 

 scruples not to affirm all to be true that is written of such vast ships ; adding, 

 that he has made it intelligible how it may be so, by finding places for the 

 zygitae, and a conveniency of moving their oars under the seats of those that 

 sat next before them. And here he shows at large, of what determinate size 

 those vessels were, according to his supposition and contrivance ; beginning 

 from a triremis, and showing how many oars and seamen it contained, namely 

 200, of which 180 were rowers, and the rest mariners. So that in the Athenian 

 fleet, of which Cono was general, consisting of 180 triremes, there were 

 36000 men. Then proceeding to a quinqueremis, with 420 men each, of 

 which there were rowers 300, and soldiers 120. So that three things were 

 stupendous in that Roman fleet at Messina, and the Carthaginian at Lyliboum ; 

 one is, that the former consisted of 330, and the latter of 350 ships, most 

 quinqueremes, that is, 150 feet long; the second, that the number of men, 

 they contained was 130000, and 150000 men; the third, the apparatus and pro- 

 vision necessary : yet all this affirmed by one of the best of the ancient his- 

 torians, Polybius ; who himself wonders at such a vast equipage. 



Here the author undertakes, out of Polybius, Plutarch and Livy, to refute 

 Salmasius, affirming, that hardly any galleys were built or equipped larger than 

 of nine tiers, called Ivvvonc. Hence he proceeds to the ships of eleven rows 

 (^IvSix.Yifn';,) and of fifteen rows (TrsvTExaKfsy.ii^n? ;) and to one of sixteen 



(lny.oiihy.ri^rt';,) 



A Letter of Mr. Isaac Newton,^ Professor of Mathematics in the 

 University of Cambridge ; containing his Neiv Theory of Light and 

 Colours : sent hy the Author to the Editor from Cambridge, Feb. 6, 

 167 1-2 ; to he communicated to the Royal Society. N" 80, p. 3075. 



SiK, — To perforin my late promise to you, I shall without further ceremony 



* This letter appears as the first public communication of the illustrious author, concerning one 

 part of his brilliant discoveries, viz. the different colour and refrangibility of tlie rays of light ; a dis- 

 covery truly novel and philosophical, and is the more extraordinary as made when the author was 

 only 23 years of age ; as appears by comparing the date of the experiments with that of his birth, 

 Dec. 25, 1642. We shall here only notice farther that he died March 20, 1727, in tlie 85th year 

 of his age J reserving the more ample account of his life and writings to the intended miscellaneous 

 Volume before mentioned. 



